The present invention relates to an improved package for dispensing individual sheets of material from a stack. In particular the present invention relates to an improvement in packages for individually dispensing sheet material formed in a stack and adhered together with a peelable adhesive layer along alternating opposing edges, e.g., in a Z-fold manner, such that one sheet of the material can be removed from the package and separated from an adjacent sheet of material without withdrawing the adjacent sheet of material.
An example of known packaging for dispensing such sheet material is depicted in FIGS. 1 and 2. As shown in FIG. 1, the package 10 includes a base 12 and a compartment 14 (a.k.a. a blister) attached to base 12. Compartment 14 is designed to contain the stack of sheet material and allow removal of individual sheets from the stack. The compartment 14 includes side walls 16, which are dimensioned to accommodate a stack of sheet material, and a cover 18 connected to the side walls 16 about the periphery of the compartment 14 to contain the stack of sheet material. The cover 18 is configured to define an opening 20 that extends across the cover 18 through which individual sheets of material can be removed from the stack. The cover also includes a pair of slits 22 at opposite ends of and transverse to opening 20 to facilitate in the removal of an individual sheet of material. The opening 20 and slits 22 thereby define a pair of opposing flanges 24 and 26. Flanges 24 and 26 each include one or more raised portions 28, which are designed to support an individual sheet of material above the cover 18 and thereby facilitate removal of the sheet.
FIG. 2, which is a cross-sectional view of FIG. 1 taken along line 2xe2x80x942, best shows the manner in which package 10 functions to dispense individual sheets of material. As shown in FIG. 2, a stack of sheet material 30 is contained within compartment 14 when compartment 14 is connected to base 12. An individual sheet of material 32 extends through opening 20 and is supported above cover 18 by raised portions 28. As is shown in FIG. 2, a biasing means is positioned within the package between the base 12 and the stack of sheet material 30. Biasing means 34 is designed to maintain the top of the stack in contact with an inner surface of cover 18 as individual sheets are removed from the stack. Sufficient contact between the top of the stack and the cover is necessary to ensure that the coefficient of friction between the inner surface of cover 18 and the top-most sheet 36 in the stack 30 within the compartment 14 is greater than that of the peelable adhesive that interconnects sheet 36 with sheet 32, as sheet 32 is removed. An insufficient contact between the top of the stack and the cover can result in multiple sheet dispensing. A package constructed as depicted in FIGS. 1 and 2 thus was designed to allow a sheet of material from a stack of interconnected sheets of material to be dispensed one at a time. In the known package of FIGS. 1 and 2, the biasing means 34 is constructed of a folded paper board material, which can be compromised in its biasing ability by conditions such as high humidity or prolonged periods of compression. Also, the use of such biasing means complicates assembly of the package (e.g., positioning and aligning biasing means between the base and the stack of material) and constitutes an additional packaging cost. The present invention is an improved package for dispensing individual sheets of material from a stack without the need for a separate biasing means between the stack of material and the base of the package.
The present invention is directed to a package for dispensing pop-up sheet material. The package comprises a compartment attached to a base, the compartment having side walls extending from the base and a cover connected to the side walls for containing the sheet material. An opening is provided in the cover to allow individual sheets to be dispensed. A pair of movable flanges are located on opposite sides of the opening, and are formed to be angularly displaced relative to the cover toward the base to thereby apply a biasing force against the sheet material in the compartment.